Early postoperative change in serum creatinine predicts acute kidney injury after cardiothoracic surgery: a retrospective cohort study.

BACKGROUND: Acute kidney injury (AKI) is one of the most severe complications after cardiothoracic surgery (CTS). However, diagnosis of AKI by elevation of serum creatinine (SCr) misses a critical time period for prevention and treatment of AKI. We have observed that patients who develop AKI show a smaller SCr decrease after CTS than those without AKI. Hence, we hypothesized that the magnitude of the SCr change (ΔSCr) measured early after CTS can predict subsequent AKI. METHODS: We conducted a retrospective analysis from January 2014 to December 2016 to examine the association of ΔSCr with AKI. ΔSCr was calculated as follows: (early postoperative SCr on intensive care unit [ICU] admission) - (preoperative SCr). Established risk factors and demographics were included in the multivariate-adjusted logistic regression model. AKI was defined by SCr criteria of the Kidney Disease: Improving Global Outcomes group. RESULTS: Among 252 patients who underwent CTS, 69 developed AKI. The median ΔSCr was - 0.14 mg/dL (range - 0.96-0.45). Patients were divided into three groups based on ΔSCr: Group 1, ≤ - 0.2 mg/dL (n = 84); Group 2, > - 0.2 to < - 0.1 mg/dL (n = 76); and Group 3, ≥ - 0.1 mg/dL (n = 92). In the multivariate analysis, Group 3 had a significantly higher incidence of AKI than Group 1 (odds ratio, 7.34; 95% confidence interval 2.55-23.3). ΔSCr was an independent risk factor for AKI (odds ratio for every 0.1-mg/dL increase in ΔSCr, 1.55; 95% confidence interval 1.23-1.97). CONCLUSIONS: A minor change in the SCr level early after CTS can predict subsequent AKI just after ICU admission.

Hypercalcemia and acute kidney injury induced by eldecalcitol in patients with osteoporosis: a case series of 32 patients at a single facility.

BACKGROUND: Eldecalcitol (ELD) is an active vitamin D3 analog that is widely used in Japan for the treatment of osteoporosis. The most common adverse drug reaction of ELD is hypercalcemia. However, few reports have focused on acute kidney injury (AKI) associated with ELD-induced hypercalcemia. MATERIALS AND METHODS: We retrospectively reviewed the medical records at our hospital for cases of hypercalcemia-induced AKI between April 2013 and February 2018. Among them, we focused on patients who developed AKI secondary to ELD-induced hypercalcemia. RESULTS: Among 69 patients who developed hypercalcemia-induced AKI, 32 patients (46.4%) developed AKI associated with ELD-induced hypercalcemia. Their mean age was 82 ± 5 years, 97% of them were female, mean corrected serum calcium level was 12.2 ± 1.5 mg/dL, serum creatinine level was 2.5 ± 2.2 mg/dL, and estimated glomerular filtration rate was 23.9 ± 14.4 ml/min/1.73 m2 on admission. ELD administration was discontinued in all patients and some of them were treated with hydration with or without calcitonin, which was followed by a normalization of serum calcium level. Corrected serum calcium level on admission was significantly higher (p < .05) in patients treated with magnesium oxide. Although there were no significant differences, serum calcium and creatine levels on admission tended to be higher in patients who were treated with other drugs that affect renal hemodynamics and renal calcium metabolism than those not taking these drugs. CONCLUSIONS: Prescribers of ELD should regularly monitor serum calcium levels and kidney function to prevent hypercalcemia and AKI associated with ELD and pay more attention to concomitant drugs especially magnesium oxide.

[Ratio of serum levels of 1,25-dihydroxyvitamin D3 and parathyroid hormone for the diagnosis and treatment of tuberculous peritonitis in a chronic kidney disease patient: a case report].

An 80-year-old man was admitted to our hospital because of exacerbation of preexisting chronic kidney disease (CKD). On admission, he showed elevated levels of serum creatinine (6.37 mg/dL) and corrected calcium (13.7 mg/dL). Although the serum levels of intact parathyroid hormone (I-PTH) and parathyroid hormone-related peptide(PTITH-rP)were low, the serum 1,25-dihydroxyvitamin D3 (1,25 (OH)2D3)levels were high. Computed tomography (CT) revealed ascites, and the ascitic fluid was exudative and serous with predominance of lymphocytes. The levels of adenosine deaminase (ADA) in the ascitic fluid were also elevated, and the results of QuantiFERON-TB2G (QFT-2G)assay were positive, indicating tuberculous peritonitits. Ascites resolved rapidly after initiation of the antituberculosis therapy. The elevated levels of serum calcium and 1,25 (OH) 2D3 returned to below-normal levels; however, serum i-PTH levels increased from 8.9 pg/ mL to 432 pg/mL. Diagnosis of extrapulmonary tuberculosis is often difficult in CKD patients. CKD patients show abnormal vitamin D activation, so these patients usually have low levels of serum 1,25(OH)2D3. On the other hand, in our patient, 1,25(OH)2D3 was extrarenally produced from tuberculous granuloma and therefore, he showed high levels of serum 1,25(OH)2D3 and correspondingly, low levels of serum i-PTH. We observed that the ratio of 1,25 (OH) 2D3:i-PTH decreased due to antituberculosis therapy. This ratio facilitated the diagnosis and evaluation of treatment for this condition.

Lidocaine-Propitocain Cream, a Eutectic Mixture of Local Anesthetics, Effectively Relieves Pain Associated With Vascular Access Intervention Therapy in Patients Undergoing Hemodialysis: A Placebo-Controlled, Double-Blind, Crossover Study.

Vascular access intervention therapy (VAIVT) is necessary to maintain vascular access in patients undergoing hemodialysis. VAIVT-associated vasodilatation is painful. However, few reports have focused on effective pain relief at the time of VAIVT. The present study was performed to determine whether lidocaine-propitocain cream, a eutectic mixture of local anesthetics (EMLA), effectively reduces VAIVT-associated pain in patients undergoing hemodialysis. This placebo-controlled, double-blind, crossover study was conducted in a single center. Among 210 patients who underwent a total of 437 VAIVT procedures from August 2017 to June 2018, 30 patients were randomly allocated to either the EMLA-placebo arm or placebo-EMLA arm at the time of VAIVT. EMLA application significantly reduced the visual analog scale score compared with placebo (47.0 ± 21.1 vs. 68.6 ± 20.7 mm, respectively; P < 0.05). EMLA is a safe and effective treatment for relief of VAIVT-associated pain in patients undergoing hemodialysis.

Long-term outcomes of idiopathic membranous nephropathy in Japanese patients treated with low-dose cyclophosphamide and prednisolone.

BACKGROUND: Treatment with cyclophosphamide and steroids for idiopathic membranous nephropathy (IMN) is effective in Caucasian patients, but the cumulative cyclophosphamide dosage exceeds 10 g and includes steroid pulse therapy. Adverse effects and difficulties with repeating treatment are major limitations. We studied the long-term outcomes of low-dose cyclophosphamide and prednisolone therapy in Japanese patients, who were thought to have relatively benign IMN compared with Caucasian patients. METHODS: This is a prospective cohort study of 103 consecutive Japanese patients with IMN and nephrotic syndrome. Patients were treated with cyclophosphamide (50 mg/day for the first 3 months and 25 mg/day for the next 3 months) and prednisolone (30 mg/day for the first week and the dosage was gradually tapered to withdraw by 2 years). Additional therapies were allowed for initial treatment failure or relapse. RESULTS: With a mean observation period of 8.5 years, 90 patients (87.4%) achieved proteinuria of <1 g/day and 78 (75.7%) achieved complete remission. A total of 27 patients did not respond to initial treatment and 30 patients had relapses after remission. Of these patients, 39 received additional therapies. At the last observation, 12 patients had developed renal insufficiency (S-Cr >1.5 mg/dL) but only 2 patients had reached renal death. Multivariate analysis revealed that the duration without remission was the strongest risk factor for renal prognosis. There were 14 deaths, and 8 patients developed cancers during the observation period. CONCLUSION: Treating nephrotic IMN in Japanese patients with low-dose cyclophosphamide and prednisolone is beneficial for long-term renal prognosis with relatively few adverse effects.

Better Oral Hygiene Habits Are Associated With a Lower Incidence of Peritoneal Dialysis-Related Peritonitis.

Some peritoneal dialysis (PD)-related peritonitis cases are thought to be caused by the pathogens in the oral cavity; however, the relationship between peritonitis and oral hygiene habits is unclear. In this study, we retrospectively examined the relationship between oral hygiene habits and peritonitis in patients who agreed to a questionnaire survey. Of the 75 patients, 37 patients developed PD-related peritonitis during the observation period. Peritonitis-free survival was significantly higher in patients who spent more time on oral hygiene daily and in patients who replaced their toothbrush more frequently (P < 0.05). According to multivariable analysis, increased daily oral hygiene duration and more frequent toothbrush replacement were associated with a significantly (P < 0.01) lower risk for peritonitis (hazard ratio [HR] 0.37 [95% CI, 0.18-0.77] and HR 0.35 [95% CI, 0.17-0.70], respectively). In conclusion, PD patients with superior oral hygiene habits showed a lower risk for PD-related peritonitis.

Severe Hypocalcemia and Resulting Seizure Caused by Vitamin D Deficiency in an Older Patient Receiving Phenytoin: Eldecalcitol and Maxacalcitol Ointment as Potential Therapeutic Options for Hypocalcemia.

An 82-year-old man treated with phenytoin for the prevention of symptomatic epilepsy was hospitalized to treat consciousness disturbance, seizure, and hypocalcemia (serum calcium: 4.6 mg/dL). Serum 25-hydroxyvitamin D level was very low (5.4 ng/mL), whereas serum calcitriol level was normal (27 pg/mL) and serum intact parathyroid hormone level was increased (369 pg/mL). He was finally diagnosed with vitamin D deficiency associated with low sunlight exposure and long-term phenytoin use for symptomatic epilepsy: phenytoin is shown to accelerate catabolism of 25-hydroxyvitamin D. Combination treatment with eldecalcitol and maxacalcitol ointments successfully normalized corrected serum calcium level: both eldecalcitol and maxacalcitol are vitamin D receptor activators used for osteoporosis and psoriasis, respectively. Our case illustrates the importance of periodic serum calcium level monitoring in patients receiving anti-epileptic drugs and the usefulness of eldecalcitol and maxacalcitol ointment as a therapeutic option for hypocalcemia, especially in countries where native vitamin D and 25-hydroxyvitamin D are not available.

A case of congenital left ventricular diverticulum in a patient with autosomal dominant polycystic kidney disease: possible mechanistic link between polycystin and ventricular diverticulum.

A 40-year-old woman had been followed as an outpatient to manage chronic kidney disease secondary to autosomal dominant polycystic kidney disease (ADPKD). Atrial premature contraction was found incidentally on an electrocardiogram during her regular follow-up examination. Subsequent transthoracic echocardiography detected an abnormal structure located very close to the left ventricular outflow tract (23 mm long × 15 mm wide in diastole). The structure was finally diagnosed as congenital left ventricular diverticulum (CLVD) using transesophageal echocardiography, contrast-enhanced computed tomography, and magnetic resonance imaging. Although CLVD occasionally causes intraventricular coagulation, lethal arrhythmia, and congestive heart failure, the size and location of her diverticulum remained unchanged over time and a 24-h Holter electrocardiogram showed no lethal arrhythmias. Accordingly, neither anticoagulation therapy nor surgical resection of the diverticulum was performed. To the best of our knowledge, ours is the first case of CLVD in a patient with ADPKD. Because gene abnormalities in polycystin coding are mechanistically related to the development of colonic diverticulum and abnormal cyst formation in ADPKD patients, we suspected that CLVD and abnormal cyst formation were related to the same gene abnormality in ADPKD. More case reports, case series studies, and basic research are required to determine whether CLVD in ADPKD is mechanistically associated with abnormal polycystin or just a coincidence.

Cholesterol Crystal Embolism Induced by Direct Factor Xa Inhibitor: A First Case Report.

An 80-year-old man presented at our hospital with renal failure. He had been treated with edoxaban, an oral direct factor Xa inhibitor, for deep vein thrombosis for 10 months prior to admission. Although the pulses in his bilateral pedal arteries were palpable, cyanosis was present in the bilateral toes. Laboratory data indicated azotemia and eosinophilia. A skin biopsy confirmed a diagnosis of cholesterol crystal embolism (CCE). Because no invasive vascular procedure was performed, we assumed that CCE was related to edoxaban. To the best of our knowledge, this is the first case report suggesting CCE induced by an Xa inhibitor.

Modified Simple Peritoneal Wall Anchor Technique (PWAT) in Peritoneal Dialysis.

♦ BACKGROUND: Outflow obstruction, a common complication in patients with peritoneal dialysis (PD), usually results in unnecessary catheter removal or replacement. This study describes a modified simple method of anchoring a PD catheter on the anterior peritoneal wall without using a laparoscopic system (peritoneal wall anchor technique, PWAT). ♦ METHODS: We performed a retrospective cohort study of consecutive PD catheter insertions, and compared the catheter survival rate between the traditional method and the modified simple PWAT. The traditional method was used in 54 cases and the modified simple PWAT was used in 17 cases. The primary endpoint was the occurrence of surgical catheter repair because of outflow obstruction by day 365. The secondary endpoint was the occurrence of catheter migration with obstruction requiring any interventions, including the alpha-replacement method by day 365. Catheter survival was analyzed by Kaplan-Meier survival curves. ♦ RESULTS: Migration-free catheter survival was significantly (p = 0.02) higher in the PWAT group (100%, 17/17) than in the traditional group (72.2%, 39/54). Catheter survival without surgical repair or cessation of PD was also significantly (p = 0.04) higher in the PWAT group (100%, 17/17) than in the traditional group (77.8%, 42/54). Similarly, migration-free and surgery-free catheter survival rates in cases with a straight-type catheter in the PWAT group were significantly higher than those in cases with a straight-type catheter in the traditional group. ♦ CONCLUSIONS: Our results suggest that the modified simple PWAT provides a better catheter survival rate than the traditional method by preventing catheter migration with obstruction in PD.

Autoimmune autonomic ganglionopathy manifesting as acute-onset orthostatic hypotension in a patient undergoing peritoneal dialysis.

Orthostatic hypotension is an important complication in the management of patients receiving dialysis therapy. As for the orthostatic hypotension caused by decreased peripheral artery resistance, diabetic neuropathy and amyloidosis are the two main causes of hypotension in dialysis patients. However, some patients develop orthostatic hypotension that is caused by dysfunction of the autonomic nervous system, not by diabetic or amyloidosis-related neuropathy. We herein present a case of a 56-year-old man with a 17-year history of peritoneal dialysis therapy, who developed acute-onset orthostatic hypotension accompanied by hypohidrosis and erectile dysfunction. Because serum autoantibodies to ganglionic nicotinic acetylcholine receptor were detected, he was diagnosed with autoimmune autonomic ganglionopathy (AAG). He was treated with high-dose immunoglobulin therapy (0.6 g per kg of body weight per day) for 5 consecutive days, which resulted in a gradual improvement in dizziness. Two months after the onset of AAG, he could discontinue vasopressors (fludrocortisone acetate and midodrine hydrochloride) and continued maintenance dialysis therapy without the use of vasopressors. This case indicates that physicians should consider autonomic neuropathy including AAG as a differential diagnosis when they encounter dialysis patients with orthostatic hypotension.

In situ expression of connective tissue growth factor in human crescentic glomerulonephritis.

Connective tissue growth factor (CTGF) has recently been recognized as an important profibrotic factor and is up-regulated in various renal diseases with fibrosis. The present study describes the sequential localization of CTGF mRNA and its association with transforming growth factor (TGF)-beta1 in human crescentic glomerulonephritis (CRGN). Furthermore, we examined the phenotype of CTGF-expressing cells using serial section analysis. Kidney biopsy specimens from 18 CRGN patients were examined using in situ hybridization and immunohistochemistry. CTGF mRNA was expressed in the podocytes and parietal epithelial cells (PECs) in unaffected glomeruli. In addition, it was strongly expressed in the cellular and fibrocellular crescents, particularly in pseudotubule structures. Serial sections revealed that the majority of CTGF mRNA-positive cells in the crescents co-expressed the epithelial marker cytokeratin, but not a marker for macrophages. Moreover, TGF-beta1, its receptor TGF-beta receptor-I, and extracellular matrix molecules (collagen type I and fibronectin) were co-localized with CTGF mRNA-positive crescents. Our results suggest that CTGF is involved in extracellular matrix production in PECs and that it is one of the mediators promoting the scarring process in glomerular crescents.

[Case of cholesterol crystal embolism occurring after treatment of cerebral infarction with urokinase].

A 74-year-old man with hypertension and diabetes mellitus was admitted to our hospital because of acute exacerbation of chronic renal failure after treatment with urokinase for a cerebral infarction. A percutaneous renal biopsy was performed to examine the cause of renal damage, revealing glomerulosclerosis and cholesterol clefts in the small arteries. Subsequently eosinophil was increased to 21% and livedo reticularis was found in the patient's foot. A skin biopsy was performed, and cholesterol clefts were again found in the small arteries. For the reason, our diagnosis was cholesterol crystal embolism. Although 30 mg of prednisolone was administered, the patient's renal function did not improve and maintenance hemodialysis therapy was necessary. This is a rare case of cholesterol crystal embolism caused by urokinase without any invasive vascular procedures.

Histologically advanced IgA nephropathy treated successfully with prednisolone and cyclophosphamide.

BACKGROUND: No definitive therapeutic consensus has been established for progressive immunoglobulin A nephropathy (IgAN). METHODS: We retrospectively investigated 35 patients with histologically advanced IgAN. The patients were divided into two groups: 27 received prednisolone and cyclophosphamide (PSL+CPA group) and 8 received supportive treatment (control group). The initial doses of PSL and CPA were 30 mg/day and 50 mg/day, respectively. PSL was tapered to 2.5 mg/day over 2 years and CPA was discontinued at 6 months. RESULTS: In the control group, mean follow-up duration was 22.9 months, renal progression rate was -20.9 x 10(-3) dl/mg per month, and all patients developed endstage renal disease within 5 years. In the PSL+CPA group, mean follow-up duration was 64.3 months, renal progression rate was -1.5 x 10(-3) dl/mg per month, and renal survival at 5 years was 89.8%. Renal prognosis was markedly improved in the PSL+CPA group compared with the control group. The patients in the PSL+CPA group were divided into two subgroups according to baseline serum creatinine (<2 mg/dl or > or =2 mg/dl); renal survival in the two subgroups was similar (84.4% versus 100% at 5 years). Adverse effects of PSL+CPA were minimal and mild. CONCLUSIONS: It is possible that PSL+CPA therapy safely improved the renal prognosis of patients with severe IgAN who would otherwise have required dialysis therapy within 5 years. However, a prospective, multicenter clinical trial is required to prove the effects and safety of this treatment.

C4d Immunohistochemistry in glomerulonephritis with different antibodies.

BACKGROUND: The presence of C4d in the kidney is generally detected particularly for the diagnosis of antibody-mediated rejection in renal transplants. In frozen sections of immunofluorescence (IF) staining with anti-C4d monoclonal antibodies (mAbs), we noted intrinsic C4d deposition even in normal glomeruli though their pathogenic or an intrinsic role is unkown. An anti-C4d polyclonal antibody (C4dpAb), which is suitable for paraffin immunoperoxidase (IP) staining, is less used than mAbs, and it has demonstrated that intrinsic C4d is not evident. To establish a stable and reproducible procedure for C4d detection with the C4dpAb and to determine the staining characteristics of it, the present study aimed to test whether the method was comparable with IF with a mAb. METHODS: We compared the C4dpAb with the mAb in adjacent sections of human diseased kidneys, and then compared IP with IF of C4dpAb. Two ways of antigen retrieval was examined for IP. RESULTS: On comparing the two antibodies for glomerular staining with IF, we found that the pattern and intensity (C4dpAb showed intrinsic C4d with IF) were similar. In addition, C4dpAb staining with IP and IF demonstrated that the intrinsic staining in the normal glomerulus was mostly undetectable by IP, whereas IF showed distinct staining. Likewise, C4d deposition with IP in some cases was apparently weaker than that on IF, suggesting that this deposition is not intrinsic but indicates pathogenic complement activation. CONCLUSIONS: The advantage of the C4dpAb for immunohistochemistry is of value for reconsidering the role of C4d in glomerular diseases.

Nodular glomerulosclerosis in patients without any manifestation of diabetes mellitus.

AIM/METHODS: Diabetic nodular glomerulosclerosis is considered to be the specific renal lesion of diabetes mellitus (DM). However, some cases, in which nodular glomerulosclerosis was found without any manifestation of DM, have also occasionally been reported. We clinicopathologically examined seven cases without a prior history of DM. They consisted of six men and one woman with a mean age of 57 years, and included three cases with family history of DM and six cases with hypertension. RESULTS: Mean body mass index was 26.2 +/- 5.9 (means +/- SD) kg/m(2) and haemoglobin A1c 5.3 +/- 1.1% or haemoglobin A1 7.0 +/- 0.6%. Mean plasma glucose levels were 5.3 +/- 0.7 mmol/L at fasting and 10.1 +/- 1.9 mmol/L at 2 h of 75 g OGTT (normal: 1 patient; impaired glucose tolerance: 4 patients; DM: 2 patients). None of them showed diabetic retinopathy in fundoscopic ophthalmoscopy. Mean serum creatinine was 268 +/- 215 micromol/L, urinary protein 5.2 +/- 4.0 g/day, and three patients had mild haematuria. Renal biopsy revealed typical nodular glomerulosclerosis, a negative deposition based on an immunofluorescence study, and neither any significant electron dense deposits nor fibrils on electron microscopy. CONCLUSION: These patients at presentation had no overt clinical manifestations of glucose intolerance. Diabetic nodular glomerulosclerosis can occur in patients without overt DM, suggesting the role of factors additional to prolonged hyperglycaemia in the pathogenesis of this disorder.

Reticulocyte hemoglobin content in hemodialysis patients with acute infection.

BACKGROUND: Reticulocyte hemoglobin content (CHr) has recently become available as a direct marker of the iron status in hemodialysis patients undergoing recombinant human erythropoietin (rHuEPO) therapy. This study evaluated the stability of CHr in hemodialysis patients with acute infectious disease. METHODS: We retrospectively selected 22 hemodialysis patients who had acute respiratory tract infection and who showed transient elevation of C-reactive protein (CRP), and we investigated changes in parameters for erythropoiesis, iron status, and inflammation, i.e., hematocrit (Ht), transferrin saturation (TSAT), CHr, serum ferritin, and CRP, in the preinfection, infection, and postinfection phases. Throughout the observation period, doses of rHuEPO and iron supplements had not been changed. We divided the patients into two groups, those who showed a decrease in Ht in the infection phase (group 1; n = 12) and those who did not show a change in Ht in this phase (group 2; n = 10). We defined the differences between the parameters in the preinfection phase and the infection phase as Delta, and performed correlation analysis between them. RESULTS: CRP in group 1 was significantly higher than that in group 2 in the infection phase. In group 1, TSAT significantly decreased, from 32.9 +/- 8.8% (preinfection phase) to 16.9 +/- 5.0% (infection phase), and CHr also significantly decreased, from 33.1 +/- 1.5 pg to 30.4 +/- 2.0 pg. In group 2, however, although TSAT significantly decreased, from 34.8 +/- 4.6% to 27.0 +/- 9.3%, CHr showed no significant change (from 33.4 +/- 0.9 pg to 33.0 +/- 1.4 pg). There was a significantly high correlation between DeltaHt and DeltaCHr, but there was a low correlation between DeltaHt and DeltaTSAT ( r = 0.505; P = 0.0153 versus r = 0.175; P = 0.4420). Furthermore, the correlation between DeltaCRP and DeltaCHr was quite high ( r = -0.722; P = 0.0001). CONCLUSIONS: TSAT overreacts to inflammation, failing to reveal the correct status of available iron for erythropoiesis in acute inflammatory disease, but the use of CHr is expected to avoid these disadvantages, providing a reliable direct marker of iron status in the acute infection phase.

Assessment of iron deficiency in chronic hemodialysis patients: investigation of cutoff values for reticulocyte hemoglobin content.

BACKGROUND: Recently, the usefulness of reticulocyte hemoglobin content (CHr) as a ferrokinetic marker in hemodialysis patients who receive recombinant human erythropoietin (rHuEPO) has been reported. However, a definite index for iron deficiency has not been established. In this study, a CHr cutoff value was investigated. METHODS: We retrospectively selected 27 hemodialysis patients by the following criteria: (1) hematocrit (Ht) values less than 30%, (2) patients receiving a stable dose of rHuEPO for at least 3 months, (3) patients who had not received iron supplements for at least 3 months, and had begun receiving iron supplements, (4) the doses of rHuEPO and iron supplements were unchanged for 8 weeks following the start of iron administration. The iron supplement was administered at a dose of 40 mg/week, and Ht, CHr, transferrin saturation (TSAT), and serum ferritin were measured. The difference between the peak Ht value obtained at weeks 4-8 and Ht at baseline was calculated (DeltaHt). Patients with a DeltaHt of 3% or more were categorized as iron-deficient at baseline (group 1; n = 17). Patients with a DeltaHt of less than 3% were categorized as iron-sufficient at baseline (group 2; n = 10). Each parameter was compared between the groups. RESULTS: Significant negative correlations between DeltaHt and CHr at baseline, and DeltaHt and TSAT at baseline were observed. CHr and TSAT were significantly lower in group 1 than in group 2 at baseline. CHr was less than 32 pg in all patients in group 1, and greater than 32 pg in nine of the ten patients in group 2. If the CHr cutoff value was 32 pg, sensitivity was 100% and specificity was 90%. CONCLUSIONS: It is considered that 32 pg is appropriate for the CHr cutoff value.